The history of Arcade is revealed! How did the former punch line become the sadistic scene stealer that now torments Marvel's teen heroes? Find out in this shocking behind-the-scenes story! Plus: what are X-23's secrets? What is Dark...

Collects All-New X-Men (2015) #17-19, Annual #1, X-Men Prime #1.Since the discovery that the Terrigen Mists-the key to unlocking an Inhuman's hidden potential and powers-are LETHAL to mutants, the X-MEN and INHUMANS have been locked i...